1. Technical Field
The present invention relates to a communication system, a transmission device, a reception device, and a communication scheme.
2. Related Art
JP-A-1994-46041 discloses an example of a clock synchronous communication system. In the system, a transmission-side device determines the level of a data signal by the time of a leading or trailing edge of a clock signal, and a reception-side device acquires the data signal level in sync with the leading or trailing edge of the clock signal to perform a processing of the acquired data signal, such as a serial-to-parallel conversion, so as to decode the signal.
In the conventional system, however, a third party can easily distinguish between the data signal and the clock signal, which makes it possible to decode the data signal by using the same processing as in the reception-side device. This causes security problems such as information leaks.